Reduce memory need

src/activities/home/HomeActivity.cpp

@@ -182,7 +182,10 @@ void HomeActivity::loadRecentBooks(int maxBooks) {
     if (!sidecar.empty()) {
       const bool sidecarAlreadyStored =
           book.coverBmpPath == sidecar || book.coverBmpPath.find("sidecar_") != std::string::npos;
+      LOG_DBG("HOME", "Sidecar for %s: stored=%s alreadyStored=%d", book.path.c_str(), book.coverBmpPath.c_str(),
+              sidecarAlreadyStored ? 1 : 0);
       if (!sidecarAlreadyStored) {
+        LOG_DBG("HOME", "Updating coverBmpPath to sidecar: %s", sidecar.c_str());
         RECENT_BOOKS.updateBook(book.path, book.title, book.author, book.series, sidecar);
         RecentBook updated = book;
         updated.coverBmpPath = sidecar;
@@ -208,7 +211,9 @@ void HomeActivity::loadRecentCovers(int coverHeight) {
       const bool isSidecar =
           FsHelpers::hasJpgExtension(book.coverBmpPath) || FsHelpers::hasPngExtension(book.coverBmpPath);
       if (isSidecar) {
+        LOG_DBG("HOME", "Converting sidecar %s for book %s", book.coverBmpPath.c_str(), book.path.c_str());
         if (!Storage.exists(book.coverBmpPath.c_str())) {
+          LOG_ERR("HOME", "Sidecar file missing: %s", book.coverBmpPath.c_str());
           RECENT_BOOKS.updateBook(book.path, book.title, book.author, book.series, "");
           book.coverBmpPath = "";
         } else {
@@ -229,6 +234,7 @@ void HomeActivity::loadRecentCovers(int coverHeight) {
             if (convertSidecarToBmp(book.path, book.coverBmpPath, w, coverHeight, name).empty()) success = false;
           }
           if (success) {
+            LOG_DBG("HOME", "Sidecar converted, placeholder: %s", placeholder.c_str());
             RECENT_BOOKS.updateBook(book.path, book.title, book.author, book.series, placeholder);
             book.coverBmpPath = placeholder;
           } else {
@@ -374,6 +380,7 @@ void HomeActivity::onEnter() {
 void HomeActivity::onExit() {
   Activity::onExit();
   freeCoverBuffer();
+  UITheme::getInstance().getMutableTheme().invalidateFrameCache();
 }
 
 bool HomeActivity::storeCoverBuffer() {
@@ -564,6 +571,9 @@ void HomeActivity::render(RenderLock&&) {
   if (!firstRenderDone) {
     firstRenderDone = true;
     requestUpdate();
+  } else if (!recentsLoaded && !recentsLoading) {
+    recentsLoading = true;
+    loadRecentCovers(getHomeCoverRenderHeight(computeHomeScreenLayout(metrics, contentRect.height, menuCount)));
   }
 }
 

src/activities/reader/ReaderActivity.cpp

@@ -62,8 +62,13 @@ std::string ReaderActivity::sidecarCoverPath(const std::string& bookPath) {
   const std::string base = bookPath.substr(0, dot);
   for (const char* ext : {".jpg", ".jpeg", ".png", ".bmp"}) {
     const std::string candidate = base + ext;
-    if (Storage.exists(candidate.c_str())) return candidate;
+    LOG_DBG("SIDECAR", "Checking: %s", candidate.c_str());
+    if (Storage.exists(candidate.c_str())) {
+      LOG_DBG("SIDECAR", "Found sidecar cover: %s", candidate.c_str());
+      return candidate;
+    }
   }
+  LOG_DBG("SIDECAR", "No sidecar found for: %s", bookPath.c_str());
   return "";
 }
 

src/components/themes/BaseTheme.h

@@ -193,6 +193,10 @@ class BaseTheme {
   // Only one of epub/xtc/txt will be non-null depending on the reader.
   virtual void onBookWillClose(const std::string& path, Epub* epub, Xtc* xtc, Txt* txt) {}
 
+  // Called when HomeActivity exits. Themes that hold heap-allocated render caches
+  // should free them here so the memory is available to child activities.
+  virtual void invalidateFrameCache() {}
+
   // ---- Shared constants and helpers for battery drawing (used by all themes) ----
   static constexpr int batteryPercentSpacing = 4;
   static void drawBatteryOutline(const GfxRenderer& renderer, int x, int y, int battWidth, int rectHeight);

src/components/themes/lyra/LyraCarouselTheme.cpp

@@ -90,9 +90,9 @@ const uint8_t* iconBitmapFor(UIIcon icon) {
 // home after settings doesn't re-read covers from SD.
 // Freed explicitly via invalidateFrameCache() before entering the reader.
 // ---------------------------------------------------------------------------
-constexpr int kFrameCount = 3;
+constexpr int kFrameCount = 1;
 uint8_t* gCachedFrames[kFrameCount] = {};
-int gCachedFrameBookIdx[kFrameCount] = {-1, -1, -1};
+int gCachedFrameBookIdx[kFrameCount] = {-1};
 int gCachedFrameCount = 0;
 std::string gCacheKey;
 
@@ -102,14 +102,8 @@ int findFrameSlot(int bookIdx) {
   }
   return -1;
 }
-}  // namespace
 
-// ---------------------------------------------------------------------------
-// Static helpers
-// ---------------------------------------------------------------------------
-void LyraCarouselTheme::setPreRenderIndex(int idx) { lastCarouselSelectorIndex = idx; }
-
-void LyraCarouselTheme::invalidateFrameCache() const {
+void freeFrameCache() {
   for (int i = 0; i < kFrameCount; ++i) {
     if (gCachedFrames[i]) {
       free(gCachedFrames[i]);
@@ -120,6 +114,14 @@ void LyraCarouselTheme::invalidateFrameCache() const {
   gCachedFrameCount = 0;
   gCacheKey.clear();
 }
+}  // namespace
+
+// ---------------------------------------------------------------------------
+// Static helpers
+// ---------------------------------------------------------------------------
+void LyraCarouselTheme::setPreRenderIndex(int idx) { lastCarouselSelectorIndex = idx; }
+
+void LyraCarouselTheme::invalidateFrameCache() { freeFrameCache(); }
 
 void LyraCarouselTheme::onBookWillClose(const std::string& /*path*/, Epub* epub, Xtc* xtc, Txt* /*txt*/) {
   if (epub) {
@@ -212,13 +214,13 @@ bool LyraCarouselTheme::tryFastHomeRender(GfxRenderer& renderer, const std::vect
 
   if (!framesReady) {
     // Free old cache and allocate fresh frames
-    invalidateFrameCache();
+    freeFrameCache();
     const int frameCount = std::min(bookCount, kFrameCount);
     for (int i = 0; i < frameCount; ++i) {
       gCachedFrames[i] = static_cast<uint8_t*>(malloc(bufferSize));
       if (!gCachedFrames[i]) {
         LOG_ERR("CAROUSEL", "tryFastHomeRender: malloc failed for frame %d", i);
-        invalidateFrameCache();
+        freeFrameCache();
         return false;
       }
     }

src/components/themes/lyra/LyraCarouselTheme.h

@@ -72,7 +72,7 @@ class LyraCarouselTheme : public LyraTheme {
                          const std::function<UIIcon(int)>& menuIcon, const char* hintBtn1, const char* hintBtn2,
                          const char* hintBtn3, const char* hintBtn4) const override;
   void onBookWillClose(const std::string& path, Epub* epub, Xtc* xtc, Txt* txt) override;
-  void invalidateFrameCache() const;
+  void invalidateFrameCache() override;
 
   void drawRecentBookCover(GfxRenderer& renderer, Rect rect, const std::vector<RecentBook>& recentBooks,
                            const int selectorIndex, bool& coverRendered, bool& coverBufferStored, bool& bufferRestored,